Some horses look lame when they are not forward. This comes down to how good a horseman/woman you are and how experienced you are to know if the horse is lame or not or if it something else. Horses don’t lie. They don’t fake lameness.
A mare at the riding school looked lame to me. I trust my instructor and he said she is not forward yet. Once the student had her forward she was not lame at all.
This is completely different to the work them until they break posted above. With the incorrect training with that philosophy you are going to end up with a lot of broken horses.
When I went to look at my boy he was NQR when his owner rode him, but later when her instructor hopped on him he was fine.
It turned out that he is cold backed, so he will not step out at all until he is warm. The NQR I saw at the start with her disappeared when I changed farriers. He has a club foot on the off fore and the other fore is pigeon toed. The farrier they were using were cutting the pigeon toed hoof back to match the club foot and that caused a very unhappy horse who did not want to go forward.